In the next generation communication system, intensive research is being conducted to provide users with services having a high data rate and various high-capacity Qualities-of-Service (QoSs). Particularly, in the current next generation communication system, Orthogonal Frequency Division Multiplexing (OFDM) scheme or Orthogonal Frequency Division Multiple Access (OFDMA) scheme is used for a Broadband Wireless Access (BWA) communication system, such as Wireless Local Area Network (WLAN) system and Wireless Metropolitan Area Network (WMAN) system, both of which are Institute of Electrical and Electronics Engineers (IEEE) 802.11 communication systems. Therefore, intensive research is being carried out on a technology for supporting high-speed services in the form of guaranteeing mobility and QoS, and an example of its typical communication system includes an IEEE 802.16 communication system.
With reference to FIG. 1, a description will now be made of a general IEEE 802.11 communication system.
FIG. 1 is a diagram illustrating a configuration of a general IEEE 802.11 communication system.
Referring to FIG. 1, the IEEE 802.11 communication system includes a terminal 101, access points (APs) of AP1 111 and AP2 113, an access point controller (APC) 121, a router 123, an Internet Protocol (IP) network 131, an Authentication, Authorization, Accounting (AAA) server 141, and a public IP network 151.
The AP1 111 and the AP2 113 are network equipments for processing a wireless access protocol with the terminal 101 that accesses the IEEE 802.11 communication system. The APC 121, network equipment for serving to control the AP1 111 and the AP2 113, provides an IEEE 802.11 communication service to the terminal 101 over the AP1 111 and the AP2 113 using the line.
The router 123 serves to perform a routing function for relaying between the APC 121 and the IP network 131, and the IP network 131 is a network for providing the IEEE 802.11 communication service to the terminal 101 that accesses the IEEE 802.11 communication system. The AAA server 141 performs authentication, authorization and accounting functions on the terminal 101 that accesses the communication system.
A description of the configuration of the general IEEE 802.11 communication system has been made so far with reference to FIG. 1. Next, with reference to FIG. 2, a description will be given of a configuration of a general IEEE 802.16 communication system.
FIG. 2 is a diagram illustrating a configuration of a general IEEE 802.16 communication system.
Referring to FIG. 2, the IEEE 802.16 communication system includes a terminal 210, Radio Access Stations (RASs) of RAS1 221 and RAS2 223 which constitute an Access Network (AN) 220, an Access Control Router (ACR) 225, an IP network 230, an AAA server 240, and a public IP network 250.
The RAS1 221 and the RAS2 223 are network equipments for processing a wireless access protocol with the terminal 210 that accesses the IEEE 802.16 communication system. The ACR 225 is network equipment for performing such functions as authentication, Medium Access Control (MAC) protocol processing, IP address allocation, and routing on the terminal 210 that accesses the communication system. The IP network 230 is a server for performing authentication, authorization and accounting functions on the terminal 210 that accesses the communication system.
A brief description of the configuration of the general IEEE 802.16 communication system has been made so far with reference to FIG. 2. Next, with reference to FIG. 3, a description will be made of a network configuration for service interworking between the IEEE 802.11 communication system and the IEEE 802.16 communication system.
FIG. 3 is a diagram illustrating a network configuration for service interworking between a general IEEE 802.11 communication system and a general IEEE 802.16 communication system.
Referring to FIG. 3, the network configuration for service interworking between the communication systems includes RASs of RAS1 310 and RAS2 312 for processing a wireless access protocol with a terminal 300 accessing the IEEE 802.16 communication system; an ACR 320 for performing such functions as authentication, MAC protocol processing, IP address allocation, and routing on the terminal 300; APs of AP1 330 and AP2 332 for processing a wireless access protocol with the terminal 300 accessing the IEEE 802.11 communication system; an APC 340 for serving to control the AP1 330 and the AP2 332; an IP network 350 for providing the IEEE 802.16 communication service and the IEEE 802.11 communication service to the terminal 300; an AAA server 360 for performing authentication, authorization and accounting functions on the terminal 300 accessing the IEEE 802.16 communication system and the IEEE 802.11 communication system; a Home Agent (HA) 370 for performing a routing function for relaying between the IEEE 802.16 communication system and the IEEE 802.11 communication system; and a public IP network 380.
As described above, the network configuration should be prepared to provide both the IEEE 802.16 communication service and the IEEE 802.11 communication service to the terminal 300. To provide the foregoing services, there is a need for a scheme capable of seamlessly providing the services over the optimal wireless access network determined according to the position and service requirements of the terminal. In addition, when the terminal intends to perform handover between different communication systems, the scheme should assign Mobile IP to support handover. However, in order to perform handover as described above, the terminal should be assigned an address of Mobile IP from the public IP network 380. This is because the terminal may suffer from a time delay such as signaling delay and traffic delay during interworking between heterogeneous communication systems.